Ping Joerg: doppler pencil probe

Yes, you do need to upgrade the sampling head to a SD-32 or better. That will run you about +/- $2k.

But still...

I just scored a SD-24 for cheap but it needs a new C&K momentary push button switch. Also, I need to see if Tek still carries the little buttons. As an aside, I picked up a calibration module (067-1413-00) that's called for in the SD-14 service manual. It's very simple inside, just two SMA females and a 50 ohm resistor (plus the big D connector, a 50 pin connector could be modified). When I get some tome, I'll document it and put it on the Yahoo tekscopes site.

tm

Cool. Actually, has anybody (e.g. JL) measured the SD-24's TDR signal with an SD-32? It's suspicious that the measured rise time of the TDR is the same as that of the sampler itself--the SRD source might be a fair amount faster.

Cheers

Phil Hobbs

Tek and Agilent do. A mainframe and a TDR head will cost roughly $40K. The new stuff isn't much better than an 11801+SD24 (well, lighter, and less jitter) which can be got on ebay for $1000 or so.

Just think of them as immovable objects, like a refrigerator or something.

Hey, now we know where all the SD heads went. Which ones do you have?

tm

No, but I'll do that on Monday.

The step source uses diode steering to make a fast, flat current step. This is similar to the "reference flat pulse generator" that started Picosecond Pulse Labs.

See Agoston's patents 4,758,736 and 4,755,742

Most of them! Lots of SD22s and SD24s and SD26s, several of the o/e converters, one feedthru sampler, a couple of the 40 GHz single-channel samplers. Maybe a dozen mainframes, several built into test racks. At original pricing, adjusted for inflation, I must have a million dollars worth of scopes and heads. The ebay pricing keeps going down.

Here's the guts of an SD24:

I've been meaning to investigate the guts of the mainframe, the fast bits.

Does that group include Waveform monitors and Vectorscopes like the Tek 1720, 1730, 1730D or the 1780R?

Yes, they sometimes do discuss the TV products.

tm

Or a rack on wheels. Big strong cast iron wheels.

Cheers

Phil Hobbs

new

The sampling head extender cables let you put the head a few inches from the DUT. One extender cable generally costs more than the mainframe.

new

There have been some of the 012-1221-00 2m cables going for $200 lately. I got one of those, to go with the $80 one I bought in 2009 when everybody was in a panic (including me, of course, since I'd just started a consulting business).

Bottom feeding has its benefits sometimes, as long as you aren't in too much of a hurry--the dealers want $800 or so for one cable.

Cheers

Phil Hobbs

I repaired some RM529 Wavefrom monitors aginst orders & in violation of multiple regulations at an Army base in '73. I only had one that partially worked, and several dead units for a TV station. One with a very badly burnt CRT. and another with a shorted power transformer. i used parts from it to fix four other units, the put all the bad parts back into the bad one. Almost ended up at Levenworth for those repairs. :)

I'm not sure we can even buy used equipment (service and calibration can be a problem) but I'll take a look. Thanks!

Gee, JL is talking about 1ps. You'd think Tek or Agilent could do that in a TDR! ;-)

New stuff? I must have missed it cruising the Agilent site.

I don't have that much space. :-( It's a good thing my scope has a logic analyzer and signal generator in it.

Buy some skyhooks and hang things from the ceiling. :)

As soon as I get my tools unpacked, that's pretty much what I plan on doing. Can't spread out? Build up! ;-)

I hope you have high ceilings. :) I had almost 40' of workbench & cart space at Microdyne. One 8' table just to hold blank copies of the test data sheets for the products that I worked with. Print them 25 to

Fortunately, test equipment is a *lot* smaller these days. I have four computers in my office (this laptop, my main work laptop and two displays, and two dedicated to tools), which is taking most of the space. The small bench on the other side only has a power supply, multimeter, AudioPrecision, and a scope (Aligent MSO-X-3104, which has a signal generator built in). So far, nothing is stacked, other than two of the laptops (only use one at a time, at least so far).

We used those industrial 'Equipto' carts to stack rackmount HP gear. Spectrum analyzers, 8660, 3325 and other equipment. It made it a lot easier to haul things to the cal lab to be repaired or certified, and feed up space on the benchs. Most techs had two or three, piles three to four feet high with equipment.

One tech had a six foot rack that was almost full of equipment with IEEE-488 and a computer to log the test results.